Leucine-rich repeat-containing protein 8A is a protein that in humans is encoded by the LRRC8Agene.[5] Researchers have found out that this protein, along with the other LRRC8 proteins LRRC8B, LRRC8C, LRRC8D, and LRRC8E, is a subunit of the heteromer protein volume-regulated anion channel (VRAC).[6] VRACs are crucial to the regulation of cell size by transporting chloride ions and various organic osmolytes, such as taurine or glutamate, across the plasma membrane,[7] and that is not the only function these channels have been linked to.
LRRC8A, AGM5, LRRC8, SWELL1, leucine-rich repeat containing 8 family member A, leucine rich repeat containing 8 family member A, leucine rich repeat containing 8 VRAC subunit A, HsLRRC8A
While LRRC8A is one of many proteins that can be part of VRAC, it is the most important subunit for the channel’s ability to function.[8][9] However, while we know it is necessary for VRAC function, other studies have found that it is not sufficient for the full range of usual VRAC activity.[10] This is where the other LRRC8 proteins come in, as the different composition of these subunits affects the range of specificity for VRACs.[11][12]
The transmembrane portion of LRRC8 proteins are similar to those in Pannexins.[13] LRRC8A alone can form a hexameric VRAC, for which the cyro-EM structure has been determined in its mice and human versions.[14][15][16]
In addition to its role in VRACs, the LRRC8 protein family is also associated with agammaglobulinemia-5.[17]
^Jentsch TJ (May 2016). "VRACs and other ion channels and transporters in the regulation of cell volume and beyond". Nature Reviews Molecular Cell Biology. 17 (5): 293–307. doi:10.1038/nrm.2016.29. PMID27033257. S2CID40565653.
^Abascal, F; Zardoya, R (July 2012). "LRRC8 proteins share a common ancestor with pannexins, and may form hexameric channels involved in cell-cell communication". BioEssays. 34 (7): 551–60. doi:10.1002/bies.201100173. hdl:10261/124027. PMID22532330. S2CID24648128.
Kubota K, Kim JY, Sawada A, Tokimasa S, Fujisaki H, Matsuda-Hashii Y, Ozono K, Hara J (April 2004). "LRRC8 involved in B cell development belongs to a novel family of leucine-rich repeat proteins". FEBS Letters. 564 (1–2): 147–52. doi:10.1016/S0014-5793(04)00332-1. PMID15094057. S2CID29283213.
Smits G, Kajava AV (July 2004). "LRRC8 extracellular domain is composed of 17 leucine-rich repeats". Molecular Immunology. 41 (5): 561–2. doi:10.1016/j.molimm.2004.04.001. PMID15183935.